VACUUBRAND MZ 2 VARIO-SP - Manual (Page 44)

page 44 of 51
Individual performance check of a pump head:
Check by measuring the pressure at the inlet port of the individual head:
Use a suitable vacuum gauge (e.g., DVR 2, cat. no.: 682902), make sure
that it is correctly calibrated, and measure the pressure at the inlet port.
A vacuum of less than 110 mbar should be indicated.
+
If the reading is higher, recheck the pump chamber and make sure
that the valves and the diaphragms are correctly seated (diaphragms
concentric with bore).
Assembling fittings
➨
Use an open end wrench (width 17) to as-
semble the screw-in fittings with connection
hose to the pump heads. In case, steady
with an open end wrench (width 20).
If the pump does not achieve the ultimate vacuum:
- Whenever the diaphragms and valves have been replaced, a break-in
period of several hours is required before the pump achieves its ulti-
mate vacuum.
- In case of an unusual noise, switch off pump immediately and check
clamping disc positions.
If the specified ultimate vacuum is not achieved, and if this does not
change after the break-in period:
Check hose connectors at pump heads for leaks. If necessary recheck
valve seats and pump chambers.
Checking the ultimate vacuum
➨
After any intervention at the equipment (e.g., repair / maintenance)
the ultimate vacuum of the pump has to be checked. Only if the pump
achieves its specified ultimate vacuum, the pump’s leak rate is low
enough to ensure that no explosive atmospheres will occur in the inte-
rior of the equipment.